From Roma termini take the train to Napoli centrale. (1hr 17 m) From Naples either take the Circumvesuvian to Sorrento (1H 30m)then a bus to Praiano (1H15m)
Total of time to do this, all three modes of transportation is (4 hours) Your best bet is to hire a private driver from Napoli central directly to Praiano. Cost will be about €120.
To travel by train from Naples to Chiusi, again take a Private driver. This train will save you some time. There are no changes.
Intercity 590
SEE SERVICES
10:31
Napoli Centrale
Fermata: Napoli Centrale
Partenza: 10:31
10:47
10:49
Aversa
Fermata: Aversa
Arrivo: 10:47
Partenza: 10:49
11:20
11:22
Formia-Gaeta
Fermata: Formia-Gaeta
Arrivo: 11:20
Partenza: 11:22
11:58
12:00
Latina
Fermata: Latina
Arrivo: 11:58
Partenza: 12:00
12:37
12:40
Roma Tiburtina
Fermata: Roma Tiburtina
Arrivo: 12:37
Partenza: 12:40
13:12
13:14
Orte
Fermata: Orte
Arrivo: 13:12
Partenza: 13:14
13:43
13:45
Orvieto
Fermata: Orvieto
Arrivo: 13:43
Partenza: 13:45
14:08
Chiusi-Chianciano Terme
For driving in Italy, download this e-book. Yellow banner on bottom of page.
https://italybeyondtheobvious.com/
Parking in Siena, use either the Stadio lot or the one by the train station. Use the escalator to the top for the station.
Drop your car in Siena after visiting Volterra and San Gimignano and take the bus to Florence. 1H17m. Then train to Venice. 2H 15m.
For trains use https://www.trenitalia.com/en.html
Amalfi coast bus timetable.
https://www.sorrentoinsider.com/en/sorrento-to-positano-bus-schedule
This blog should give you an idea of getting around in Praiano. It’s one of the prettiest towns on the coast but please take note of the stairs with the twins.
https://iowagirleats.com/life-on-the-mediterranean-coast/